Machine for grinding down conical points of drawn steel rods



E. D. DEAN ET AL MACHINE FOR GRINDING DOWN CONICAL Oct. 31, 1950 POINTS OF DRAWN STEEL RODS 4 Sheets-Sheet 1 Filed April 1, 1947 eg/z lNVENTORS WI I Jun PER mm H. i y

r {PM ATTORNEYS 4 Sheets-Sheet 2 INVENTORS aw 2P PER W -11 1 ATTORNEYS E. D. DEAN ET AL MACHINE FOR GRINDING DOWN CONICAL POINTS OF DRAWN STEEL RODS an m A F 0 M Oct. 31, 1950 E D DEAN ETA 2,528,042

. L MACHINE FOR GRINDING DOWN CONICAL POINTS OF DRAWN STEEL RODS Filed April 1, 1947 4 Sheets-Sheet 3 INVENTORS MIMI- PER W H 7 PT/WM ATTORNEYS Oct. 31, 1950 E. D. DEAN ET AL 2,523,042

MACHINE FOR GRINDING DOWN CONICAL POINTS OF DRAWN STEEL RODS Filed April 1, 1947 4 Sheets-Sheet 4 INVENTORS PER W WW l -4.11444! l-M ATTORNEYS l atented Oct. 31, 1950 UNITED STATES PATENT OFFICE MACHINE FOR GRINDING DOWN CONICAL POINTS OF'DRAWN STEEL RODS Elliott D. Dean, Putnam, Conn., and Arthur H; Rogers, North Billerica, Mass, assignors, by mesne assignments, to The Putnam Needle Company, .a corporation of Connecticut Application April 1', 1947, Serial No. 738,552

9 Claims. l

This is a machine for grinding down the conical points of cylindrical drawn steel rods to make needles for use in phonographs, the resulting needles being cylindrical at the base or shank part, then having an annular shoulder at substantially right angles to the axis, then a middle portion of less diameter than the shank and then a relatively short conical point or tip. The purpose is to accomplish this grinding down in one continuous operation and at high' speed.

In making such phonograph needles, the drawn steel rods are now ordinarily first formed with a conical point at one end and then this point with a portion of the cylindrical shank which is to be held in the phonograph are cut off at the desired length. The cut end of the cylindrical rod is tapered usually by being ground down to form a conical point. This new pointed end and part of the shank is cut on and the process is repeated until almost theenti-re length of the rod has been used up.

We have found however that with some sound reproducing machines, such as phonographs it is desirable to make a needle with a cylindrical shank or holding part which may be the untreated part of the original rod andto form between it and the pointed tip amiddle cylindrical portion of less diameter than the shank and to accomplish this by first making a conical point of theangle desirable for the finishedtip and to then cut away, as by grinding, the metal .be= tween what is to be the finished tipwand the base of the original cone and usually part of the shank or holding portion so that the middle part remaining will have a cylindrical form and between it and the shank or holding part there will be an annular shoulder or collar between theshank and the middle portion which lies in a plane substantially perpendicular to the axis of the rod and of the finished needle.

I With such a needle it is possible to have a more delicate vibration or tone than can be obtained by the usual type of conically pointed needle.

To produce such a cylindrical middle portion of reduced size has been difficult because of the' amount of material that must be removed at and near the base of the conical point-and usually at the adjoining part of theshank as such grinding results in the rim or face of the grinding wheel wearing away faster at that side which is doing thegrinding near the base than at the other side of the face which is not required toreniove as much material and in fact does not reach the smaller part of the original conical point until after the other side of the face has donev a great deal of grinding.

'Toprocure the desired result has'required a large number of processes which took time, were; expensive and slowed production. I

'With this machine the rods with the pointed ends are placed on an apron, the points being substantially lined up on a side feed guide, the

apron being so arranged that the rods will move up in each groove.

The feed roll carries these rods along past a finishing" guide which causes each point as it comes up to be alined each in exactly the same position below and before a grinding wheel travelling at a surface speed of from six to seven thousand feet per minute so set as to grind down the conical point and if desired, part of the cylindrical holding shank to form the cylindrical middle portion specified;

At the same time there are a revolving wheels each of which enters an annular groove in the feed roll and each of which is so positioned that while the point is being ground; these wheels revolve the rod which is being ground so that all its parts are equally treated but the points are not in contact with anything.

By our machine'and method of revolving each rod from 25 to times while it is moving and being ground down, we can finish over 5000 treated rods per hour.

As the edge of the rim of the grinding wheel must do more grinding near the base of the conical point'than near the tip, it wears down much more rapidly and one of the main purposes of this device is to reshape the rim or face after such wearing down so that the desired portion or the original conical point will be a cylinder instead of a cone.

We are aware-that there are machines having an automatic feed associated with a grinding wheel to reduce the ends of cylindrical members such as shown in patent to Anderson, No.

2,170,672, and we are aware that there are other machines of a similar automatic type to produce cones with conical points on the ends of cylin'-' drical members such as are'particularly useful in making skewers and toothpicks as in patent-to Spinney, No. 1,175,831, but the particular dilli culty of producing the results desired in this case by means of a substantially automatic "machine" was the fact that the face of the grinding wheel would constantly wear'down on the side nearest the base of the cone.

To overccme this difficulty, we provide aj dresser which includes a very hard cutting point, such as a diamond, so carried by a cutter holder that it can move in a direction parallel with the axis and across the face 'of the grinding wheel" while it is in motion such axis being parallel I with the axis of the 'feed roll" and with the axis of the rods. As this alignment is always main-' p'lu-ral-ity of rod tained, the grinding face of the wheel is kept cylindrical, instead of conical, and it therefore grinds down the middle portion of each rod. so

to the axis of the rod being ground which is" parallel to the axis of the grinding wheel and of the feed roll.

As the reshaping gradually cuts down the diameter of the grinding wheel, it is necessary that the dresser cutter carrier should have a radial as well as an axial motion and it is also necessary that the cutting face of the grinding wheel should be moved towards the rods on which it is being operated, and it is further desirable that the speed of the grinding wheel should be so its speed can be increased.

These various movements such as. the axis parallel motion of the dresser cutting member, its radial movement, the radial movement of the grinding wheel towards the work and its speed must all cooperate with the feed-roll and rod turning mechanism.

Other provisions are plows, which enter the annular grooves in the face of the feed roll to plow out or throw out the finished rods and preferably the grinding wheel is entirely enclosed and is provided with a suction mouth connected with air exhausting mechanism to carry oif the dust from the grinding wheel and from the points.

Figure l is an enlarged elevation of the end of a drawn steel rod showing in dotted lines the portion cut out by our new machine and a portion of a grinding wheel.

-Figure 2 is a plan view of our machine with certain parts exaggerated in size for clarity.

Figure 3 is a side elevation of our device.

Figure. 4 is a front elevation of our device shown as slightly tilted.

Figure 5 is an enlarged detailed front elevation showing one form partly in section.

Figure 6 is a view similar to Figure 5, showing the dresser device in a different position and vice shown in Figures 5 and 6.

Figure 8 is an enlarged detailed side elevational" view showing the relation of our rod revolving wheels, feed roll and grinding wheel guard.

Figure 9 is a side elevation of a preferred form of dresser device. a

Figure 10 is a front elevation and Figure 11 is a plan view of the device shown in Figure 9.

In Figure 1, W is a drawn steel rod, having a base portion I00 and a conical tip [0! which ends in a point I132. The dotted lines define the portion of conical tip llll and I00 which is to be ground out by our device, leaving a cylindrical middle portion I03 and shoulder I 04, each substantially perpendicular to the other.

After passing through our device and. being ejected therefrom, the newly ground tip of rod W together with a desired length of base portion I00 is cut oif from the remainder of the base, the cut off portion forming a' phonograph needle. Rod Wis then given a new conical point,

by any well known means, and may be again in serted in our device until such time as it becomes too short to feed roll 75.

- As shown in Figure 2, we provide a hopper with a feed apron 913, a side feed guide 95 and op-- posite side 95, the apron being approximately;

of our dresser device beeffectively held in grooved v to take care of the short sections as fed by the feed apron and roll.

thesame with as the grooved feedroll 15 To facilitate the passage of rods W toward the feed roll, we prefer to use a feed apron in which the bottom is divided into sections, each at a different inclined plane, as at SH, 92, 93 and 94, with one section 9'! at a decided slope adjacent to'the feed roll.

F represents the frame of our device, comprising legs L and a top plate A to which the various parts are bolted or otherwise fastened. We may use an convenient source of power but prefer to use an electric motor M, having a shaft I to which are keyed two power pulleys 2 and 58.

Pulley 50, by means of belt El and pulley 56 drives a gear reduction box 54, having a power shaft 53 which carries a large pulley 55 anda sprocket ll. Sprocket H is connected by chains '12 and sprocket 13 to grooved feed roll 15 there-y by revolving it in a clockwise direction.

, We provide a plurality of longitudinal grooves 76 in feed roll 15, of a width and depth suflicient to accommodate only one rod W, the rod when in groove 16, being buried so that its top surface is proximate the outer surface of feed roll 15.

Each groove 16 is milled out at a slight angle from the radius of the feed roll so that it rakes forward in the direction of rotation and so that its trailing edges will form a hook for better picking up and retaining shown in Figure 8.

1 We also provide a plurality of annular grooves '1! in each feed roll 15, into which plows 69 as well as rod revolving wheels 61 extend. Plows 69 are of springy sheet metal and reach under each rod W, after its tip has been ground, and lift it out of its groove 76 channeling it into the collecting bin 18.

Each pick up groove 76 is of a size to allow a' rod to revolve freely without binding and to be pushed down by the rod revolving wheels 67 against its inner face so that it cannot come out but can turn freely. Each groove 18 is of such a depth measured from the inner face of an annular groove "that a small segment of rod projects into groove H and is in contact with the wise direction by large pulley 55 by means of pulleys-52 on shaft 202 and belts 201 and are carried at the ends 62 of rocker levers 60, journaled in bearings 6i. p

Because after the desired needle shape has been made, and the needle end of the rod cut off, it is desirable to use up the rest of that rod as far as possible. The cut end can be tapered in the usual manner but as the rod is constantly getting shorter, we found it desirableto have the.

annular grooves 71 on the feed roll 75 and the rod revolving wheels 67 so arranged that the wheels can be moved axially to engage any one or two of the series of annular grooves so as they are .We therefore provide thumb screws 20! in the hub of each pulley 52 for tightening said pulleys at the desired point along-shaft 202, and provide a slot 203 in shaft '202 towhich each pulley 52 a is keyedin a well known manner.

of each rod W as we also provide thumb screwsfi'll on the opposite end of levers 60 which bear against the flat top of gear box 50 to adjust the pressure on rod revolving wheels 31. We can thus cause rods W to revolve at varying speeds depending on the slippage permitted between the rod and the rubber surface 68 of wheels 61.

As shown in Figure 4, top A of frame F may be horizontal but we prefer to tilt it at an angle of 5, more or less, so that the rods W will tend to slide toward side feed guide 95 by gravity.

The rods leave side guide 35 and then engage a finishing guide l! which after each one is picked up by. the feed roll correctly lines up their points with reference to the grinding wheel 12 but releases them before they are engaged by the rod revolving wheels 61 and just before they are engaged by the grinding wheel l2. Their points are therefore correctly lined up before the rods are being turned by the rod revolving wheels and asthey are being ground down or being reshaped by the grinding wheel. The rod revolving wheels G'Imay turn clockwise or anti-clockwise.

Powered by the same motor M, as drives the feed mechanism, is a pulley 2 which is connected tora speed changing device D of a well known type. D comprises a shaftfi, pulleys l and 0 and hand adjusting knob l, which when turned slides the pulleys on intermeshing inclined planes thereby changing the speed of revolution of the driven pulley 6.

A belt 8 connects pulley 6 with a pulley 0 keyed to a shaft i 0, journaled in a bearing i, the shaft 10 carrying at its opposite end the grinding wheel 12. We provide a pulley guard 13 fixed at one end of shaft E0 to a bearing carrier 55 which slides vertically in a carrier track l3. Also fixed to carrier 55 is a dressing device 22 so that the grinding wheel and dresser may be lowered gradually as the diameter of the grinding wheel is reduced by use. Carrier I5 is threaded on a worm ii, having a ratchet l8 operated by a pawl 29 and handle 20, whereby a movement of the handle will lower the carrier if: a measured amount.

.Grinding wheel guard I l is fixed to carrier track Hi, is not slidable and is slotted at the top at 2!, to accommodate the dresser 22, at the bottom, at 23, to accommodate feed roll 15 and in the middle, at 206, to accommodate shaft it). We provide a. face plate 24, which extends close to feed roll T5 to protect theoperator and to confine the products of the grinding. At the other side of guard M is an opening 25, proximate the point of grinding, to which is attached a suction pipe 26, leading to an exhausting pump not shown, for the purpose of pneumatically by suction removing the particles of ground material from the machine.

Our dressing device as shown in Figs. 2-7 may comprise a diamond point or tip H0, held by a threaded tube 21 having an adjusting knob 23 adapted to raise or lower the diamond .cutting tip when the knob is turned. Tube 21 is carried at the end of a. sliding member 29, operating in a guide 30, and slidable by means of pivoted handle 3!.

In operation, our grinding wheel while working on the conical tip of rod W, tends to acquire a tapered or beveled surface, as shown in Figure 1. By occasionally working the handle 3! of our dressing device, however, the operator can move diamond tip H0 slowly across the face of the grinding wheel as it revolves at high speed, thus recutting a cylindrical surface.

It is obvious that if, a taperedcut on rod W was desired, rather than a cylindrical out, we could use our dresser to make and maintain a tapered surface on the grinding wheel ii.

We may use, in place of the dresser previously shown at H0, 21 and 28, a preferred form of dresser shown at N in Figs. 9-11. Dresser N is carried by a sliding member 329, operating inua.

guide 30 and is slidable by means of a handle 3| across the face of the grinding wheel l2.

Dresser N is attached to 329 by a bolt 330 and may be tightened by lock nut 33l in a position perpendicular to the face of grinding wheel l2 or at various angles from=the perpendicular if it is desired to bring into contact with the grinding surface, a particular face of the diamond cutting point 332.

Diamond 332 is fixed in a tubular holder 333, the latter being held in a threaded shaft 30! by set screw 334. Shaft 30! is slidable in frame 335 and is prevented from turning therein by lugs 3 operating in slots 312.. A ratchet 302'is threadedly connected to shaft 30E and is operable by a spring pressed pawl 303 pivoted to a handle.

304. A handle 305 is also provided, for raising or lowering shaft 33 I when pawl 303 is held out of contact with ratchet 302 by the tightening of set screw 3H]. Stops 30-6, 300, adjustable in slots 301, 301, ar provided to limit the movement of handle 304 to the extent desired and a leaf spring 308 bears against ratchet 302 thereby maintaining it in position.

We claim:

1. In a machine for forming a cylindrical section from proximate the base to proximate the tip of the drawn steel conical point of a rod; the combination of feed apron to support a plurality of such rods; a feed roll having a plurality of pick up grooves parallel with its axis each to pick upa rod and a plurality of annular grooves; means to aline the tips of the rods at a point before they are to be revolved and ground; means to revolve each rod comprising a plurality of rod revolving wheels, each entering an annular feed roll groove; grinding means comprising a grinding wheel for grinding the points of each rod as it is being revolved; dresser means including a cutting point and carrier therefor, said carrier being slidable parallel with the axis of the feed roll and the pick up grooves and means to move it radially towards th axis of the feed roll to keep the grinding face of the grinding wheel as a cylinder with an axis parallel with the axis of the feed roll and of the axis of the rod being ground; means to move the grinding wheel radially towards such rod axis;

- means to increase the speed of said grinding Wheel as it is reduced in diameter; and means to remove the finished rods from the feed roll including plows engaging the annular grooves in the feed roll.

2. In a machine for forming a cylindrical section from proximate the base to proximate the tip of the drawn steel conical point of a rod; the combination of feed apron to support a plurality of such rods; a feed roll having a plurality of pick up grooves parallel with its. axis each to pick up a rod and a plurality of annulargrooves; means to aline the. tips of the rods at a point be fore they are to be revolved and ground; means to revolve each rod comprising a plurality of rod revolving Wheels, each entering an annular feed roll groove; grinding means comprising a grind ing wheel for grinding the points of each. rod as it is being rovolved; dresser means to keep the grinding surface of the grinding wheel as a cylinder with an'axis parallel with the axi of the feed tip of the drawn steel conical point of a red; the

combination of feed apron to support a plurality of such rods; a feed roll having a plurality of pick up grooves parallel with its axis each to pick up a rod and a plurality of annular grooves; a side guide to aline the tips of the rods at a point before they are to be revolved and ground; means to revolve each rod comprising a plurality of rod revolving wheels, each entering an annular feed roll groove; grinding means comprising a grinding wheel for grinding the points of each rod as it is being revolved; means to move the grinding wheel radially towards such rod axis; means to increase the speed of said grinding wheel as it is reduced in diameter; and means to remove the finished rods from the feed roll including plows engaging th annular grooves in the feed roll.

4. In a machine for forming a cylindrical section from proximate the base to proximate the tip of the drawn steel conical point of a rod; the combination of feed apron to support a plurality of such rods; a feed roll having a plurality of pick up grooves parallel with its axis each to pick up a rod and a plurality of annular grooves; means to aline the tips of the rods at a point before they are to be revolved and ground; means i to revolve each rod comprising a plurality of rod revolving Wheels, each entering an annular feed roll groove; grinding means comprising a grinding wheel for grinding the points of each rod as it is being revolved; means to move the grinding wheel towards such rod axis; means to increase the speed of said grinding wheel as it is reduced in diameter; and means to remove the finished rods from the feed roll including plows engaging the annular grooves in the feed roll.

5. In a machine for forming a cylindrical section from proximate the base to proximate the tip of the drawn steel conical point of a rod; the combination of a feed apron which slopes laterally toward the points of such rods to support a plurality of such rods; a feed roll having a plurality of pick up grooves, the walls of each of which grooves slope forward and are of a greater depth than the diameter of a rod, parallel with its axis each to pick up a rod and a plurality of annular grooves; a side guide to aline the tips of the rods at a point before they are to be revolved and ground; means to revolve each rod comprising a plurality of rod revolving wheels, each entering an annular feed roll groove; grinding means comprising a grinding wheel for grinding the points of each rod as it is being revolved; dresser means to keep the grinding surface of the grinding wheel as a cylinder with an axis parallel with the axis of the feed roll and of the rod being ground; means to move the grinding wheel towards such rod axis; means to increase the speed of said grinding wheel as it is reduced in diameter; and means to remove the finished rods from the feed roll including plows engaging the annular grooves in the feed roll.

6. In a machine for forming a cylindrical section from proximate the base to proximate the tip of the drawn steel conical point of a rod; the combination of a feed apron which slopes lateral- 1y toward the points of such rods to support a plurality of such rods; a feed roll having a plu-' rality of pick up grooves/the walls of each of which grooves slope forward and are of a greater depth than the diameter of a rod, parallel with its axis each to pick up a rod and a plurality of annular grooves; means to aline the tips of the rods at a point before they are to be revolved and ground; means to revolve each rod comprising a plurality of rod revolving wheels, each entering an annular feed roll groove; grinding means comprising a grinding wheel for grinding the points of each rod as it is being revolved; means to move the grinding wheel as it is reduced in diameter; and means to remove the finished rods from the feed roll including plows engaging the annular grooves in the feed roll.

7. In a continuous action machine for forming a cylindrical section from proximate the base to proximate the tip of the drawn steel conical point of a rod; the combination of a feed apron which slopes laterally towards the points of such rods to support a plurality of such rods and slopes downward and forward at its inner bottom and at a predetermined angle; a feed roll having a plurality of pick up grooves, the walls of each of which grooves slope forward and are of greater depth than the diameter of a single rod and less than the diameter of two such rods, whereby the outer face of the wall of each roll groove will be substantially in extension of the bottom front section of the feed apron when proximate thereto, such grooves being parallel with the axis of said roll, each to pick up a single rod, there being a plurality of annular revolving wheel grooves in the feed roll; means to revolve each rod at a predetermined position, such means comprising a.

plurality of rod revolving wheels, each entering an annular feed roll wheel groove; grinding means comprising a grinding wheel for grinding the point of each rod at a predetermined position as each rod is being revolved by the rod revolving wheels and is moving with the feed roll; and means to revolve the feed roll, the rod turning wheels and the grinding wheel in the same direction at different speeds.

8. In combination with the subject matter of claim 7, means to align the tips of the rods before they are to be revolved and ground.

9. In combination with the subject matter of claim 7, together with means to align the tips of the rods before they are to be revolved and ground; and means to dress the cutting face of the grinding wheel while it is turning and grindmg.

ELLIOTT D. DEAN. ARTHUR H. ROGERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 993,981 Grover May 30, 1911 1,017,881 Landis Feb. 20, 1912 1,061,063 Freeman et al May 6, 1913 1,175,831 Spinney Mar. 14, 1916 1,508,939 Reeves Sept. 16, 1924 1,531,281 Garbin Mar. 31, 1925 1,772,042 Heim Aug. 5, 1930 2,170,672 Anderson Aug. 22, 1939 2,302,304 Elberty Nov. 17, 1942 2,397,459 Armbrust Apr. 2, 1946 2,454,988 Bunker Nov. 30, 1948 

